Gogeometry Problem 1076

 dans Euclide Geometry Problem par Harvey Littleman

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From Gogeometry

Using :

• Isometric transformation
• Additional points
• congruent triangles

• Define α = ∠BAF and β = ∠DAE
• α+β+45°=90° => α+β = 45°
• Define E’ rotation of E anticlockwise with an angle of 90°
• =>AE=AE’, β = ∠DAE = ∠BAE’
• ∠FAE’= α+β = 45°
• ΔFAE’ is congruent to ΔFAE (SAS) => FE’=FE
• Therefore a+b=x

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